Warp drive is having a renaissance. Scientists revealed the first physical model of a warp drive, the holy grail of space travel that would allow us to bend the fabric of space and time to our will and conquer the huge distances that separate humanity from the stars. Another astrophysicist has now made a similarly exciting warp drive discovery.
Until now, scientists have gradually chipped away at the dream of faster-than-light (FTL) travel by relying on bizarre physics and exotic matter hypotheses. Erik Lentz of Göttingen University, however, has devised a theoretical design of a warp drive that is genuinely anchored in conventional physics in a new paper. Lentz’s theory overcomes the need for a source of exotic matter in previous designs by reimagining the shape of warped space.
To put it another way, we’ll get you up to (warp) speed. The name “warp drive” is derived from science fiction, most notably Star Trek. The FTL warp drive of the Federation works by smashing matter and antimatter and transforming the explosive energy into propulsion. According to Star Trek, this extraordinary strength alone propels the ship at FTL speeds.
The thought of a warp drive is enticing simply because space is enormous. It would take more than 100,000 years for a modern, chemically burning rocket to travel to Alpha Centauri, our nearest star system. Even if humans could travel at the speed of light, which is theoretically impossible, a one-way trip would still take four years. We’re not going to make it to a neighboring star system without warp drive.
Our present knowledge of warp speed dates back to 1994, when a now-iconic theoretical physicist named Miguel Alcubierre postulated what has since been known as the Alcubierre drive. To accomplish superluminal transport, the Alcubierre drive conforms to Einstein’s theory of general relativity.
“By a purely local expansion of spacetime behind the spaceship and an opposite contraction in front of it,” Alcubierre wrote in his paper’s abstract, “motion faster than the speed of light as seen by observers outside the disturbed region is possible.”
To contract and twist space-time in front of it and form a bubble, an Alcubierre drive would spend a massive amount of energy—likely more than what is available in the universe. Inside the bubble, explorers would be in an inertial reference frame with no correct acceleration. Within the bubble, the rules of physics would still apply, but the ship would be localized outside of space.
Alcubierre’s idea is based on using enormous quantities of energy to generate a bubble of exotic matter—in this case, negative energy. What is the problem? There is no known mechanism in particle physics that can produce this negative energy.
That leads us to Lentz’s paper, which appears in the new issue of the peer-reviewed journal Classical and Quantum Gravity. Lentz discloses a new approach for building a warp drive utilizing conventional physics and without the need for heretofore unrecognized kinds of exotic matter in it.
Lentz discovered specific types of spacetime bubbles that scientists had overlooked after analyzing prior studies on warp drives. These bubbles resembled solitons, which are compact waves that preserve their form while travelling at a constant velocity. (Think of a single ripple steadily moving across a calm lake.) Lentz rederived Einstein’s equations for different soliton configurations until he found one that worked with conventional energy sources and without the need for any exotic matter.
“This work has moved the problem of faster-than-light travel one step away from theoretical research in fundamental physics and closer to engineering,” Lentz said in a statement:
“The next step is to figure out how to bring down the astronomical amount of energy needed to within the range of today’s technologies, such as a large modern nuclear fission power plant. Then we can discuss making the first prototypes.”
Lentz’s warp bubble still fails to overcome one of the most major obstacles to FTL travel: the enormous amount of energy required to warp spacetime.
According to Lentz, creating a warp bubble for a 656-foot-wide spaceship traveling at the speed of light requires nearly 100 times the energy contained in Jupiter’s mass. That’s roughly 30 orders of magnitude more powerful than current nuclear reactors. “Fortunately, several energy-saving mechanisms have been proposed in earlier research that can potentially lower the energy required by nearly 60 orders of magnitude,” he said.
Meanwhile, Lentz believes that the plasmas around extremely magnetic neutron stars are a natural place to look for positive-energy solitons.
In other warp drive news, scientists at Applied Physics‘ Advanced Propulsion Lab (APL) have released the world’s first model for a physical warp drive in Classical and Quantum Gravity. Like Lentz’s research, this model also flies in the face of what we’ve long thought about warp speed travel: that it requires exotic, negative forces.
The APL approach, like the current paradigm, uses floating bubbles of spacetime rather than floating ships in spacetime. Though Alcubierre has accepted this model, it is still very much in the “far future” zone of possibilities, made up of notions that scientists have yet to figure out how to construct in any manner. The APL scientists write:
“While the mass requirements needed for such modifications are still enormous at present, our work suggests a method of constructing such objects based on fully understood laws of physics.”
Let’s hope the “far future” isn’t as far as it sounds. That could be the case if scientists continue to make discoveries in warp drive technology.